Śivasaṃhitā 5.222

Secret practice (guhya-abhyāsa) is not concealment but creating a protective space for what is most fragile and precious: consciousness in the process of transformation. Just as a newly lit flame needs shelter from the wind before consolidating, the yogi’s practice needs the refuge of inner retreat before being robust enough to function in any condition.

Guhya = secret, hidden (from guh = to conceal, the root also giving guhā = cave, the inner space of the heart in the Upaniṣads), kriyate = is performed, abhyāsa = sustained practice, saṅgaṃ tyaktvā = having abandoned attachment, tadantare = in the interior of that (the retreat).

The guhā as image of the inner heart and the guhya as qualifier of practice share the same root. In the Upaniṣads, the Absolute is described as dwelling in the guhā hṛdayasya (the heart’s cave). The yogi’s secret practice reproduces this condition: descends to the inner cave of the heart where Brahman has always dwelt. External secrecy protects the inner secret.